.358 ar from .223 brass?? POSSIBLE??

[Hamish]

If yous guys ask nicely, tommygirlMT might tell you about her 8x223 AR.

[rockrat]

Tried it using 357 max brass and turning the rim to 223 specs. Problem was the rib in the front of the mag would shove the round towards the center of the mag and impede feeding. I think you could use 7.62 x 39 brass and use the front part of a 35rem reamer and just chamber deep enough to use the x39 brass. Cut off 35 rem dies for sizing and seating.

I would think 9mm mag brass would work the best.

[MJR007]

I was going to rebarrel my 25wssm AR15 upper to a 358wssm but never did. I just sold it to geezer56.

[mongoosesnipe]

i dont think it could be done with 223 brass there are 2 versions of the 338 whisper one is off the 7mm br round and the other is a straight walled 221/ or cut down 223 case i am pretty sure 338 is about the biggest you can fit into a 223 case you could do it with a 6.8 case which can accommodate up to a 10mm slug or use 10mm mag brass which shared head dimensions with the 6.8

[Artful]

i dont think it could be done with 223 brass there are 2 versions of the 338 whisper one is off the 7mm br round and the other is a straight walled 221/ or cut down 223 case i am pretty sure 338 is about the biggest you can fit into a 223 case you could do it with a 6.8 case which can accommodate up to a 10mm slug or use 10mm mag brass which shared head dimensions with the 6.8

Don't tell Winchester or Jeff Cooper (his was call 9mm super cooper for use in south american carry)


or if you want to stretch it out

9x19mm para, 9mm on shortened 223 wildcat, and .223 rem

[mongoosesnipe]

i stand corrected

Don't tell Winchester or Jeff Cooper (his was call 9mm super cooper for use in south american carry)


or if you want to stretch it out

9x19mm para, 9mm on shortened 223 wildcat, and .223 rem

[Artful]

mongoosesnipe, don't feel bad - I've been watching this stuff for almost half a century.
Wildcat rounds and factory trial stuff that will make your head spin - biggest issue is getting any self feeder to feed 'em.
Lots of good rounds didn't catch on - just look at the Long Road from 300 Whisper to 300 Blackout.

[mongoosesnipe]

it would appear to need inside neck reaming that's why i dismissed it as not practical

I am amazed at how fast the blackout has caught on considering how long the whisper and its knock offs have been around it is an impressive piece of marketing for a cartridge that isn't all that practice out side of sub sonic suppressed applications i have had a whisper ar for about 10 years its neat but not the wonder cartridge that people make it out to be

[leadman]

I think Mike Bellm has a 357 max/300 whisper chambering for the T/Cs. One of the big named shooters also used the max in a 300w barrel that had been cut for the rim. Just a matter of changing the extractor to go from one to the other.

[Artful]

it would appear to need inside neck reaming that's why i dismissed it as not practical

I am amazed at how fast the blackout has caught on considering how long the whisper and its knock offs have been around it is an impressive piece of marketing for a cartridge that isn't all that practice out side of sub sonic suppressed applications i have had a whisper ar for about 10 years its neat but not the wonder cartridge that people make it out to be

Timing is everything - currently there is a surge of interest in suppressed guns and cartridges for cast boolit shooting seems to be making more headway - not as much Magnumitis as in my youth, Plus of course AR / AK / black rifle fever started by the Administration. I always think of my 300 Fireball as a self-loading 30-30. And it is neat with subsonic loads, but then again I'm partial to quiet guns these days. I would at some point like to try a 9x39 in a bolt action with a can.

[mongoosesnipe]

I did some playing around and it took 4 different dies working up incrementally and 6 steps but I opened the neck of a 223 to 9mm and straight walled the case the bullet can be seated in the old neck which is thinner so no inside reaming required if this market ever calms down I might take this project further but for now i give you 9x45mm aka "9 thrillameter"

[Artful]

I like it. Did you have to anneal it between steps?

[mongoosesnipe]

i tried annealing but it didn't seem to help with splinting i actually had to go up to .375 then back down to 9mm to straighten out the body the first one i did was unannealed and it worked then it split a few unannealed then a few annealed then back to unannealed i am sure it would have went smoother with virgin brass

[Artful]

Wonder if after the panic we can get some 223 basic cases (un-necked) to play with - this could be an real interesting project.

[mongoosesnipe]

I like the idea of it as it would use a standard ar mag the case holds 30 gr of varget with a 147gr 9mm HP on top of it which is pretty decent i didnt try ant other powders but that gives it a 20% gain in powder capacity over the 223 could have pretty good potential with h110

[xacex]

For the AR platform to shoot it would just require reaming out a 9mm barrel, and drilling a gas hole. I think that you would have extraction problems with so much surface area against the chamber unless you used a larger than normal gas port to get the bolt to yank it out. but it is also possible that there would be no issues due to the powder charge you would be using. It looks like the 450 Bushmaster, but sized down. 357 Bushmaster? I don't want to give them any ideas....

[mongoosesnipe]

I said 9 thrillmeter I wouldn't dare curse it by associating it with the shrub master name...also 9mm is a tapered case it is larger at the base than this cartridge .391 vs .377 so you would need to start with an I unchambered 9mm barrel

[357Mag]

Mr. Jake -

Howdy !

Even were it a straight-walled case...
.378" base diam - .358" bullet diam = .020". Divide by 2 = .010" thick case ( "neck" ) walls.,
That would be insufficiently robust of a case, for use in an "AR" app.

Another potential "parent " case might be had, but would bring w/ it a likely one-off rim diam.

Take a look @ .351 Win self-loading, for example.

A .30 Rem or .32 Rem case could be made to work, after necking-up to .358" cal.... and there's already an AR bolt/bolt face
for that case' rim diam.

A .357 AutoMag would require a .308 bolt face... amongst other considerations for it to be a viable AR choicee.


With regards,
357Mag

[mongoosesnipe]

The 6.8 case (30 rem) would be the next best bet but then mag selection drops off but powder charge would go up and the case could have a little tapper

[GARD72977]

I think Mike Bellm has a 357 max/300 whisper chambering for the T/Cs. One of the big named shooters also used the max in a 300w barrel that had been cut for the rim. Just a matter of changing the extractor to go from one to the other.

Im not a big name shooter but I have a Virgin Valley 300/221 rimmed that they built for me around 2000. It takes a lot of work to form the cartridge but I really like it. I was shooting 22cal handgun Sil back then and wanted to try the big bore. I ended up divorced and moved before the bbl was finished. It has hit lots of cans but no steel.